18.7.14.3 Function blockIEC10000286-1-en.vsdI103POSCMDBLOCKPOSITIONSELECTIEC10000286 V1 ENFigure 255: I103POSCMD function block18.7.14.4 SignalsTable 535:I103POSCMD Input signalsName Type Default DescriptionBLOCK BOOLEAN 0 Block of commandPOSITION INTEGER 0 Position of controllable objectSELECT BOOLEAN 0 Select of controllable object18.7.14.5 SettingsTable 536:I103POSCMD Non group settings (basic)Name Values (Range) Unit Step Default DescriptionFunctionType 1 - 255 - 1 1 Function typeInfNo 160 - 236 - 4 160 Information number for command output18.7.15 Operation principle18.7.15.1 GeneralIEC 60870-5-103 is an unbalanced (master-slave) protocol for coded-bit serialcommunication exchanging information with a control system, and with a data transferrate up to 38400 bit/s. In IEC terminology, a primary station is a master and a secondarystation is a slave. The communication is based on a point-to-point principle. The mastermust have software that can interpret IEC 60870-5-103 communication messages.Introduction to IEC 60870–5–103 protocolIEC 60870-5-103 protocol functionality consists of the following functions:• Event handling• Report of analog service values (measurements)• Fault location1MRK 511 365-UUS A Section 18Station communicationPhasor measurement unit RES670 2.1 ANSI 661Technical manual
